Index: Makefile.inc1
===================================================================
--- Makefile.inc1
+++ Makefile.inc1
@@ -128,10 +128,25 @@
 TARGET_ABI=	gnueabi
 .endif
 .endif
-MACHINE_ABI?=	unknown
-MACHINE_TRIPLE?=${MACHINE_ARCH:S/amd64/x86_64/:C/hf$//:S/mipsn32/mips64/}-${MACHINE_ABI}-freebsd13.0
-TARGET_ABI?=	unknown
-TARGET_TRIPLE?=	${TARGET_ARCH:S/amd64/x86_64/:C/hf$//:S/mipsn32/mips64/}-${TARGET_ABI}-freebsd13.0
+MACHINE_VENDOR?=	unknown
+TARGET_VENDOR?=		unknown
+
+# The triple has the general format <arch><sub>-<vendor>-<sys>-<abi>
+# See https://clang.llvm.org/docs/CrossCompilation.html#target-triple
+.ifndef MACHINE_TRIPLE
+MACHINE_TRIPLE?=${MACHINE_ARCH:S/amd64/x86_64/:C/hf$//:S/mipsn32/mips64/}-${MACHINE_VENDOR}-freebsd${FREEBSD_REVISION}
+.ifdef MACHINE_ABI
+MACHINE_TRIPLE:=${MACHINE_TRIPLE}-${MACHINE_ABI}
+.endif
+.endif
+
+.ifndef TARGET_TRIPLE
+TARGET_TRIPLE?=	${TARGET_ARCH:S/amd64/x86_64/:C/hf$//:S/mipsn32/mips64/}-${TARGET_VENDOR}-freebsd${FREEBSD_REVISION}
+.ifdef TARGET_ABI
+TARGET_TRIPLE:=${TARGET_TRIPLE}-${TARGET_ABI}
+.endif
+.endif
+
 KNOWN_ARCHES?=	aarch64/arm64 \
 		amd64 \
 		arm \
@@ -534,10 +549,6 @@
 .endif
 
 # Set VERSION for CTFMERGE to use via the default CTFFLAGS=-L VERSION.
-.if !defined(_REVISION)
-_REVISION!=	${MAKE} -C ${SRCDIR}/release MK_AUTO_OBJ=no -V REVISION
-.export _REVISION
-.endif
 .if !defined(_BRANCH)
 _BRANCH!=	${MAKE} -C ${SRCDIR}/release MK_AUTO_OBJ=no -V BRANCH
 .export _BRANCH
@@ -548,7 +559,7 @@
 .export SRCRELDATE
 .endif
 .if !defined(VERSION)
-VERSION=	FreeBSD ${_REVISION}-${_BRANCH:C/-p[0-9]+$//} ${TARGET_ARCH} ${SRCRELDATE}
+VERSION=	FreeBSD ${FREEBSD_REVISION}-${_BRANCH:C/-p[0-9]+$//} ${TARGET_ARCH} ${SRCRELDATE}
 .export VERSION
 .endif
 
@@ -567,7 +578,7 @@
 .elif ${_BRANCH:M*-p*}
 EXTRA_REVISION=	_${_BRANCH:C/.*-p([0-9]+$)/\1/}
 .endif
-PKG_VERSION=	${_REVISION}${EXTRA_REVISION}
+PKG_VERSION=	${FREEBSD_REVISION}${EXTRA_REVISION}
 .endif
 .endif	# !defined(PKG_VERSION)
 
@@ -1808,7 +1819,7 @@
 
 package-pkg: .PHONY
 	rm -rf /tmp/ports.${TARGET} || :
-	env ${WMAKEENV:Q} SRCDIR=${.CURDIR} PORTSDIR=${PORTSDIR} REVISION=${_REVISION} \
+	env ${WMAKEENV:Q} SRCDIR=${.CURDIR} PORTSDIR=${PORTSDIR} REVISION=${FREEBSD_REVISION} \
 		PKG_CMD=${PKG_CMD} PKG_VERSION=${PKG_VERSION} REPODIR=${REPODIR} \
 		WSTAGEDIR=${WSTAGEDIR} \
 		sh ${.CURDIR}/release/scripts/make-pkg-package.sh
@@ -3393,5 +3404,5 @@
 			ln -sf ../../${XDTP}/usr/bin/$$i \
 			    ../../../../usr/bin/${XDDIR}-$$i; \
 			ln -sf ../../${XDTP}/usr/bin/$$i \
-			    ../../../../usr/bin/${XDDIR}${_REVISION}-$$i; \
+			    ../../../../usr/bin/${XDDIR}${FREEBSD_REVISION}-$$i; \
 		done
Index: Makefile.libcompat
===================================================================
--- Makefile.libcompat
+++ Makefile.libcompat
@@ -17,7 +17,7 @@
 .if ${WANT_COMPILER_TYPE} == gcc || \
     (defined(X_COMPILER_TYPE) && ${X_COMPILER_TYPE} == gcc)
 .else
-LIB32CPUFLAGS+=	-target x86_64-unknown-freebsd13.0
+LIB32CPUFLAGS+=	-target x86_64-unknown-freebsd${FREEBSD_REVISION}
 .endif
 LIB32CPUFLAGS+=	-m32
 LIB32WMAKEENV=	MACHINE=i386 MACHINE_ARCH=i386 \
@@ -49,9 +49,9 @@
 .endif
 .else
 .if ${TARGET_ARCH:Mmips64el*} != ""
-LIB32CPUFLAGS=  -target mipsel-unknown-freebsd13.0
+LIB32CPUFLAGS=  -target mipsel-unknown-freebsd${FREEBSD_REVISION}
 .else
-LIB32CPUFLAGS=  -target mips-unknown-freebsd13.0
+LIB32CPUFLAGS=  -target mips-unknown-freebsd${FREEBSD_REVISION}
 .endif
 .endif
 LIB32CPUFLAGS+= -mabi=32
Index: lib/clang/llvm.build.mk
===================================================================
--- lib/clang/llvm.build.mk
+++ lib/clang/llvm.build.mk
@@ -1,6 +1,7 @@
 # $FreeBSD$
 
 .include <src.opts.mk>
+.include <meta.sys.mk>
 
 .ifndef LLVM_SRCS
 .error Please define LLVM_SRCS before including this file
@@ -10,6 +11,10 @@
 .error Please define SRCDIR before including this file
 .endif
 
+.ifndef FREEBSD_REVISION
+.error Please define FREEBSD_REVISION before including this file
+.endif
+
 .PATH:		${LLVM_SRCS}/${SRCDIR}
 
 CFLAGS+=	-I${SRCTOP}/lib/clang/include
@@ -29,14 +34,16 @@
 TARGET_ABI=	-gnueabihf
 .elif ${TARGET_ARCH:Marm*}
 TARGET_ABI=	-gnueabi
+.elif defined(TARGET_ABI)
+TARGET_ABI:=	-${TARGET_ABI}
 .else
 TARGET_ABI=
 .endif
+
 VENDOR=		unknown
-OS_VERSION=	freebsd13.0
 
-LLVM_TARGET_TRIPLE?=	${TARGET_ARCH:C/amd64/x86_64/:C/arm64/aarch64/}-${VENDOR}-${OS_VERSION}${TARGET_ABI}
-LLVM_BUILD_TRIPLE?=	${BUILD_ARCH:C/amd64/x86_64/:C/arm64/aarch64/}-${VENDOR}-${OS_VERSION}
+LLVM_TARGET_TRIPLE?=	${TARGET_ARCH:C/amd64/x86_64/:C/arm64/aarch64/}-${VENDOR}-freebsd${FREEBSD_REVISION}${TARGET_ABI}
+LLVM_BUILD_TRIPLE?=	${BUILD_ARCH:C/amd64/x86_64/:C/arm64/aarch64/}-${VENDOR}-freebsd${FREEBSD_REVISION}
 
 CFLAGS+=	-DLLVM_DEFAULT_TARGET_TRIPLE=\"${LLVM_TARGET_TRIPLE}\"
 CFLAGS+=	-DLLVM_HOST_TRIPLE=\"${LLVM_BUILD_TRIPLE}\"
Index: share/mk/local.meta.sys.mk
===================================================================
--- share/mk/local.meta.sys.mk
+++ share/mk/local.meta.sys.mk
@@ -242,10 +242,6 @@
 
 .if ${MACHINE:Nhost:Ncommon} != "" && ${MACHINE} != ${HOST_MACHINE}
 # cross-building
-.if !defined(FREEBSD_REVISION)
-FREEBSD_REVISION!= sed -n '/^REVISION=/{s,.*=,,;s,",,g;p; }' ${SRCTOP}/sys/conf/newvers.sh
-.export FREEBSD_REVISION
-.endif
 CROSS_TARGET_FLAGS= -target ${MACHINE_ARCH}-unknown-freebsd${FREEBSD_REVISION}
 CFLAGS+= ${CROSS_TARGET_FLAGS}
 ACFLAGS+= ${CROSS_TARGET_FLAGS}
Index: share/mk/src.sys.env.mk
===================================================================
--- share/mk/src.sys.env.mk
+++ share/mk/src.sys.env.mk
@@ -23,6 +23,11 @@
 RELOBJTOP?=	${RELTOP}
 RELSRCTOP?=	${RELTOP}
 
+.if !defined(FREEBSD_REVISION)
+FREEBSD_REVISION!= sed -n '/^REVISION=/{s,.*=,,;s,",,g;p; }' ${SRCTOP}/sys/conf/newvers.sh
+.export FREEBSD_REVISION
+.endif
+
 # site customizations that do not depend on anything!
 
 # Save MAKEOBJDIRPREFIX and don't let src-env.conf modify it.